Bonding olefin polysulphide plastics to flexible bases



April 16, 1940.

BONDING OLE FIN POLYSULPH E. EGER 2,197,127

IDE PLASTICS T0 FLEXIBLE BASES Filed March 4, 1937 Olefine p ly ifhide plastic Uncured rubber Com osition Flexible base INVENTOR. Efi/Vi E62 ATTORNEYS Patented Apr. 16, 1940 BONDING onarm roLYsuLrmna r'uis'rlcs 'ro rm-zxmm mass m am, Grosse Pointe, Psi-amen, m... by mcsne, assignments, to United States Rubber Company, New York,

Few Jersey N. Y., a corporation of Application March '4, 1937, Serial No. 128,989

comm.

This invention relates to improvements in bonding olefln polysulphide plastics to flexible I An object of the invention is to provide an article normally flexible in use and embodying a fabric, and as a result the polysulphide plastic flexiblebase, for example, rubberized fabric material, so bonded to a coating of an olefln polysulphide plastic as to' avoid cracking, peeling or breaking ofl of the plastic coating due to flexing of the. article during use.

Olefin polysulphide plastics such as those referred to in Patrick U. S. P. 2,049,974 and U. S. P. 1,981,968, and particularly the member which is known as Thiokol (believed to be ethylene u polysulphide) are useful as a coating for various bases because it is substantiallyimpervious to fluids such as water and gases. However, when applied directly to a flexible or fabricated base which undergoes 'va ous degrees'of flexing under go conditions of using.

for the Thiokol to break up or loosenor peel ofl.

e same, there is a tendency This especially occurs where the polysulphide plastic is applied as a coating over the band ply of a'tire.. The band ply is a rubberized fabric u on the inside of the'tubeless tire, and may have one or more skim coats of vulcanized rubber.

. when the tire undergoes repeated flexure, various strains are set up in and surrounding the does not remain integral with and strongly j bonded to the fabricated base. While I have this problem in mind,'it is to be understood that the advantages of the present invention may be applied wherever it is sought to flrmly'and permanently bond a substantially continuous and unbroken coating of the polysulphide plastic to a flexible foundation base which undergoes marked degreesof flexing in use.

According to the invention the fabric which a maybe rubberized or otherwise treated is first coated in any suitable manner as by spraying or brushing with a layer of a non-curing rubber cement, preferably one containing a resin flux. j

.use, embodying a flexible fabricated base bonded applied the desired ,coatingor coatings of theolefln polysulphide plastic, for example Thiokol.

o The dried cement acts as a strong bonding agent between the flexible base and the polysulphide plastic coating. It also acts as an elastic cushion for thepolysulphide coatingso as to maintain it as a solid continuous and unbroken fllm or .1 layer even under the most severe flexing and heat conditions during use of the article. The general assembly is shown in the-appended drawing. The following example is given in illustration of a guru cement that serves the above purpose, although it is to be understood that the proportions of the ingredients including the rosin or its equivalent may be varied. The parts are by weight.

-Example.4'l pounds of unvulcanized rubber, 85 lbs, of rosin, and 68 gallons of 68 solvent asoline are treated as follows: The rubber is milled to soften it and added to the gasoline-with churning until substantially completely dissolved. Then the rosin is added and the mix churned until the rosin is "dissolved. The mix is then ready for use. I

The method of bonding hereinabove set forth may be used when applied to other flexible articles than tires, for example it may be applied to balloon fabrics and the like and other flexible articles where it is desired to exclude .or retain water, air, or other gases.

Unvulcanized or uncured rubber herein is to be understood as including not only new or raw rubber but also reclaimed rubber.

I Having thus described my invention, what I claim-and desire to protect by Letters Patent is:

1. An article normally freely flexible during use, embodying a flexible fabricated base rendered impervious to fluids by a substantiallycomtinuous coating of an olefln polysulphide plastic, including a binder between the said base and the plastic coating which binder is a soft elastic layer of gum composition free of vulcanizing ingredients indirect contact with said coating.

2. An article normally, freely flexible during use, embodying a flexible fabricated base bonded,

to a. fluid impervious substantially continuous to a fluid impervious substantially continuous coating of ethylene polysulphide by means of a soft elastic dried layer. of an uncured rubber-resin -cement free of vulcanizing ingredients in direct contact with said coating.

4. An article normally freely flexible during use, embodying a flexible rubberized fabric base embodying a coating of vulcanized rubber bonded to a fluid" impervious substantially continuous.

coating of an olefln polysulphide plastic bymeans of a soft elastic dried layer of an uncured rubber-- is.

10 impervious to fluids.

6. An article normally freely flexible during 3,197,127 resin cement free of vulcanizing ingreidents in use, embodying a flexible fabricated base rendered impervious to fluids by a coating of an olefin polysulphide plastic and an intermediate bonding layer of a dried non-curing gum cement free of vulcanizing ingredients in direct contact with said coating between said base and coating whereby to render the said coating substantially immune to breakuf; on fiexure oi said base during use,

ERNST EGER. 

